CN114072092A

CN114072092A - System and method for selecting and marking positions on dental appliances

Info

Publication number: CN114072092A
Application number: CN202080028290.4A
Authority: CN
Inventors: 乔什·隆; 克里斯托弗·扬西; 托尼·索拉雷克; 克莱特·卡尔普
Original assignee: Smithrecht Club Co
Current assignee: Smithrecht Club Co
Priority date: 2019-02-12
Filing date: 2020-02-11
Publication date: 2022-02-18
Also published as: US20200257766A1; WO2020167766A1; US11288410B2; MX2021009740A; US10482192B1

Abstract

Systems and methods for marking dental appliances are described herein. A method for marking dental appliances includes receiving a digital model corresponding to a dental appliance. The digital model includes an arch that contains a plurality of teeth. The method also includes determining whether a portion of the teeth on the right or left side of the arch include a flatter occlusal surface and selecting the portion having the flatter occlusal surface, identifying surfaces on the teeth of the selected portion that are flat relative to other surfaces on the teeth of the selected portion, determining a best fit line between the flat surfaces, and marking the appliance with a mark based on the best fit line.

Description

System and method for selecting and marking positions on dental appliances

Cross Reference to Related Applications

This application claims benefit and priority from U.S. application No. 16/686,040 filed on 15/11/2019 (which is a continuation of U.S. application No. 16/273,893 filed on 12/2/2019), the contents of both of which are hereby incorporated by reference in their entirety.

Background

The present invention generally relates to manufacturing dental appliances (dental aligners). More particularly, the present disclosure relates to marking dental appliances.

Dental impressions provide negative impressions of the teeth and oral tissue. The negative impression can then be used to produce a physical or digital copy of the tooth. Typically, a tray having a viscous thixotropic impression material therein is fitted over the arch of a patient's teeth. The impression material becomes solid, leaving an impression of the tooth structure in the mouth. The impression provides a detailed and stable negative of the teeth when taken out of the mouth. Optionally, the impression is processed using a digital scanning method to create a digital negative of the tooth.

After successfully imprinting and creating an orthomodel or model of the dental impression, the supplier may create dental appliances from the orthomodel of the dental impression. The supplier may create the dental appliances by thermoforming plastic onto the positive mold. Typically, such thermoforming is performed by an individual.

The manufacture of the dental appliances may be accomplished in a facility that produces dental appliances for a number of different patients. In addition, realigning a patient's teeth using dental appliances may require the use of many different appliances for the same patient. As a result, facilities may produce a large number of dental appliances, and tracking and organizing the appliances may be difficult.

SUMMARY

One embodiment relates to a method for marking a dental appliance. The method includes receiving a digital model corresponding to a dental appliance. The digital model includes an arch that contains a plurality of teeth. The method also includes determining whether portions of the teeth on the right or left side of the arch include a flatter occlusal surface and selecting portions having flatter occlusal surfaces, identifying surfaces on the selected portions of the teeth that are flat relative to other surfaces on the selected portions of the teeth, determining a line of best fit between the flat surfaces, and marking the appliance with a marking based on the line of best fit. As used herein, the terms "flat," "flattest," and the like are intended to mean any surface that is flat, substantially flat, flatter than some other surfaces, flatter than most other surfaces, meets or exceeds a threshold relative to at least one other surface, and the like.

Another embodiment relates to a system for marking dental appliances. The system includes a processing circuit. The processing circuitry includes at least one processor and a memory storing instructions. When executed by at least one processor, the instructions cause the processing circuit to receive a digital model corresponding to a dental appliance. The digital model includes an arch that contains a plurality of teeth. The instructions also cause the processing circuitry to determine whether portions of the teeth on the right or left side of the arch include a flatter occlusal surface and select the portion having the flatter occlusal surface, identify surfaces on the selected portion of the teeth that are flat relative to other surfaces on the selected portion of the teeth, and determine a best fit line between the flat surfaces. The system also includes a marking system configured to mark the dental appliance with a mark based on the best fit line.

Another embodiment relates to a memory storing instructions. When executed by the processor, the instructions cause the system to receive a digital model corresponding to the dental appliance. The digital model includes an arch that contains a plurality of teeth. The instructions also cause the system to determine whether portions of the teeth on the right or left side of the arch include a flatter occlusal surface and select the portions having the flatter occlusal surface, identify surfaces on the selected portions of the teeth that are flat relative to other surfaces on the selected portions of the teeth, determine a best fit line between the flat surfaces, and provide the best fit line to a marking system configured to mark the dental appliance with a mark based on the best fit line.

Brief Description of Drawings

Fig. 1 is an illustration of a dental appliance marking system according to an exemplary embodiment.

Fig. 2 is an illustration of a method of marking a dental appliance according to an example embodiment.

FIG. 3 is an illustration of a graphical user interface displaying a digital model of a patient's teeth according to an exemplary embodiment.

Fig. 4 is an illustration of a graphical user interface displaying a digital model of a patient's teeth and a flat surface for marking dental appliances, according to an example embodiment.

FIG. 5 is an illustration of the graphical user interface of FIG. 4 displaying a digital model and a flat surface from another view according to an exemplary embodiment.

FIG. 6 is an illustration of the graphical user interface of FIG. 4 displaying a digital model and a flat surface from another view according to an exemplary embodiment.

Detailed Description

Before turning to the figures, which illustrate certain exemplary embodiments in detail, it is to be understood that the disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It is also to be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

Referring generally to the drawings, described herein are systems and methods for marking digital appliances. In various embodiments, the system receives one or more digital models representing the orthodontic positions of the patient's teeth. In one example, a patient or dental professional creates an impression of the patient's teeth. The impression is then scanned to create a digital model (e.g., an "initial digital model") of the patient's current tooth position. Alternatively or additionally, the dental professional uses a scanning system to create the initial digital model. Once the initial digital model is created, the digital model is used to create a digital model (e.g., a "final digital model") representing a final orthodontic position of the patient's teeth, and the final digital model is used to create one or more digital models representing one or more intermediate orthodontic positions through which the patient's teeth will be directed to reach the final orthodontic position (e.g., a "corrective digital model") using the dental appliances.

Once the one or more remediated digital models are created, the manufacturing system is used to manufacture one or more physical models, each physical model corresponding to a remediated digital model or a final digital model. For example, a three-dimensional ("3D") printer may be used to fabricate one or more physical models. The dental appliances are then manufactured using the one or more physical models. In some embodiments, the dental appliance is produced by thermoforming a plastic sheet over the physical model. Further, in some embodiments, a plurality of dental appliances are manufactured for each physical model. As an example, three appliances may be manufactured for each digital model, where each of the three appliances has a different stiffness (e.g., based on a stiffness of a material used to manufacture the appliance or based on a thickness of a material used to manufacture the appliance). By wearing the dental appliances (e.g., in a predetermined sequence), the patient's teeth move from their initial positions in the patient's mouth to final positions modeled in the final digital model.

The facility that manufactures dental appliances typically manufactures a large number of dental appliances at a given time. Thus, to ensure that the correct dental appliance is provided to the correct patient, each dental appliance may be provided with indicia identifying the dental appliance. For example, the indicia may identify the patient with which the dental appliance is associated and the positions at which the dental appliance fits a predetermined sequence of tooth positions of the patient (e.g., in a treatment plan for the patient). As another example, each appliance may be assigned a label that an individual may look up in a database to identify the patient and where the appliances fit in a predetermined sequence. Alternatively, the dental appliances may be marked to identify the dental appliances to the patient. As an example, the dental appliances may be marked to indicate which dental appliance in the predetermined sequence the patient should wear next. The process of determining the location of these marks on the appliance and creating these marks is described in further detail below.

Referring now to fig. 1, an embodiment of an appliance marking system 100 is shown. As shown in fig. 1, the system includes a model memory 102, an appliance marking computing system 104, and a marking system 106. The model memory 102, the appliance marking computing system 104, and the marking system 106 are operably connected. In some embodiments, at least some of the model memory 102, appliance marking computing system 104, and marking system 106 may be connected via a network (e.g., the internet, a wide area network, a local area network, etc.). In other embodiments, at least some of the model memory 102, appliance marking computing system 104, and marking system 106 may alternatively or additionally have wired connections. Further, in some embodiments, at least some of the model memory 102, appliance marking computing system 104, and marking system 106 may be located in the same facility. In other embodiments, at least some of the model memory 102, appliance marking computing system 104, and marking system 106 may be located in geographically separate facilities. As an example, the model memory 102 may be configured as a cloud storage system accessible by the appliance tagging computing system 104 via the internet, where the appliance tagging computing system 104 is located in the same facility as the tagging system 106. As another example, the appliance marking computing system 104 may be located in a first facility and the marking system 106 may be located in a second facility. Accordingly, the marking system 106 may retrieve instructions for marking dental appliances from the appliance marking computing system 104 via a network (e.g., via an internal file sharing program, via the internet, etc.).

As shown in FIG. 1, model store 102 includes a digital model database 108. Digital model database 108 is configured to receive and retrievably store one or more digital models 110. For example, the digital model database 108 may receive one or more digital models 110 from a separate computing system that creates the digital models 110. In some embodiments, the one or more digital models 110 stored in the digital model database 108 include a final digital model 110 and a corrective digital model 110 for a given patient. In other embodiments, the one or more digital models stored in digital model database 108 include one or more digital models used to fabricate physical models. For example, the final digital model and the remediated digital model may be reformatted to 3D print the physical model based on the final model and the remediated model, and these modified models may be saved in the digital model database 108.

The appliance indicium calculation system 104 includes an appliance indicium location circuit 112. As shown, the appliance indicia positioning circuit 112 is operatively connected to the digital model database 108 and is configured to retrieve the digital model 110 from the digital model database 108. By way of example, the digital model database 108 may store the digital models 110 in a sequential order (e.g., based on a time at which the models were received, based on last names of patients, etc.), and the brace mark locating circuit 112 may be configured to retrieve the digital models 110 in a sequential order. As another example, the appliance indicia positioning circuitry 112 may be configured to retrieve the digital model 110 based on the manufacture of the corresponding physical model (e.g., retrieve the digital model based on a time at which the physical model corresponding to the digital model is to be manufactured).

Once the appliance indicia positioning circuit 112 has retrieved a given digital model, the appliance indicia positioning circuit 112 is configured to determine a location for marking any appliances manufactured from the physical model corresponding to the digital model. For example, in some embodiments, the appliance marker positioning circuit 112 is configured to determine a position for marking the appliance by identifying a sequence of flat areas on the occlusal surface of the posterior tooth side, as described in further detail below with reference to fig. 2.

As shown in fig. 1, the appliance indicium calculation system 104 further includes an appliance indicium placement circuit 114 operatively connected to the appliance indicium positioning circuit 112. The appliance marking layout circuit 114 is configured to determine a layout of markings at appliance marking locations determined by the appliance marking positioning circuit 112. By way of illustration, the appliance indicium layout circuitry 114 may determine how the indicium fits the appliance indicium location. For example, the indicia may be a string of alphanumeric characters (e.g., a string of text). In some embodiments, the appliance marking layout circuit 114 is configured to generate markings for appliances. In other embodiments, the appliance marking layout circuit 114 is configured to receive markings of appliances, for example, from a centralized database that assigns and stores markings of appliances manufactured for various patients. Further, in some embodiments, more than one dental appliance may be manufactured from the same physical model, as described above. In such embodiments, each dental appliance may include a different indicia, and the appliance indicia layout circuit 114 may be configured to determine the layout of each particular dental appliance accordingly. For example, the rectifier mark layout circuitry 114 may determine a layout from a plurality of layout options (e.g., layout options that change the font, font size, characters, and/or format of the mark). Alternatively, in other embodiments, all of the dental appliances manufactured from a given physical model may include the same indicia, and the appliance indicia layout circuit 114 may instead generate one layout for all of the dental appliances corresponding to a given digital model.

As shown in fig. 1, the appliance indicium computing system 104 further includes a memory 116, the memory 116 including an appliance indicium database 118. As further shown, the appliance indicia database 118 is operatively connected to the appliance indicia layout circuit 114. Accordingly, the appliance indicia layout circuit 114 is configured to provide appliance indicia layout information (e.g., a layout of indicia for a dental appliance) to an appliance indicia database 118, the appliance indicia database 118 retrievably storing the appliance indicia layout information.

Marking system 106 includes an etching system 120. As shown in fig. 1, the etching system 120 is operatively coupled to the memory 116 of the appliance marking computing system 104 and is configured to retrieve appliance marking layout information for a given appliance from the appliance marking database 118. The etching system 120 is further configured to use the appliance marking layout information to mark a correspondingly manufactured dental appliance with a mark according to the appliance marking layout information to produce a marked dental appliance 122. For example, the etching system 120 may include a laser that etches indicia into the manufactured dental appliance based on the layout determined by the appliance indicia layout circuit 114. As another example, the etching system 120 may include a computer numerical control ("CNC") machine configured to etch indicia into the manufactured dental appliance based on the layout. Further, it should be understood that while the marking system 106 shown in fig. 1 includes the etching system 120, in other embodiments, the marking system 106 may include another system for marking the dental appliances (e.g., an ink printing system or a 3D printing system).

It should be appreciated that although the components of the system 100 are shown as separate components in the embodiment of fig. 1, in some embodiments, one or more of the model memory 102, appliance marking computing system 104, and marking system 106 may be combined into the same device or system. For example, the appliance marking computing system 104 may be implemented as part of the marking system 106.

Referring now to fig. 2, an embodiment of a method 200 of marking dental appliances is shown. In various arrangements, the method 200 is implemented by the system 100 shown in fig. 1, and thus, reference is made to the components of the system 100 in describing the method 200 below. At operation 202, a digital model of a patient's teeth is received. By way of illustration, fig. 3 shows an example of a portion of a digital model 300 (including three posterior teeth 302 on one side). In various embodiments, such as the digital model 300 of fig. 3, the digital model corresponds to a physical model that has been or will be used to manufacture one or more dental appliances for a patient. For example, the digital model may be a corrective digital model representing an intermediate correction of the tooth positions of the patient's teeth or a final digital model representing the final tooth positions of the patient's teeth.

Referring back to fig. 2, at operation 204, the rear teeth of the digital model are divided into a right portion and a left portion. For example, the digital model may include an arch of the patient that includes all of the patient's teeth. Teeth can be classified as right molars and premolars (e.g., teeth 5-8 or teeth 5-7 on the Palmer numbering system) as well as left molars and premolars. In another example, the digital model includes an arch that includes fewer than all of the teeth of the patient, and thus excludes the rearmost molars or portions of the rearmost molars on each side of the arch.

At operation 206, a portion of the posterior teeth having a flatter occlusal surface is determined. As an example, in some embodiments, each tooth is represented in the digital model as a set of polygons (e.g., triangular faces). Further, each digital model may be defined in an x-direction, a y-direction, and a z-direction, where the z-direction is associated with an occlusal surface of the tooth. Thus, at operation 206, the appliance labeling computing system 104 may determine a face normal vector (face normal vector) of the polygon visible from the z-direction, the face normal being defined as a unit vector extending in the x-direction, the y-direction, and the z-direction and perpendicular to the polygon face. Next, the appliance labeling computing system 104 may determine the z-component of each face normal vector, where the z-component represents how flat its associated polygon is with respect to the z-direction (e.g., more flat because a z-component closer to 1 means that the surface of the polygon is more perpendicular to the z-axis). The appliance labeling computing system 104 may then sum the z-components of all the face normal vectors for each posterior portion of the tooth and divide the sum by the number of polygonal faces in that portion to produce an average face normal z-component for that portion. Portions of the posterior teeth having an average surface normal z-component closer to 1 are determined to have flatter occlusal surfaces in the z-direction and, for example, have more markable surfaces than teeth in other portions. Thus, in operation 208, a portion having a flatter occlusal surface is selected.

At operation 210, a flat surface on the selected portion of the teeth is identified. In some embodiments, identifying a planar surface includes determining whether a z-component of a surface normal vector of each polygon making up the selected posterior tooth is greater than or equal to a threshold. For example, in some arrangements, the threshold is 0.85. If the z-component of the surface normal vector for a given polygon is greater than or equal to a threshold value (e.g., 0.85), the appliance labeling computing system 104 selects the polygon. Each selected set of consecutive polygons correspondingly forms a planar surface of a selected posterior tooth.

As an example of the foregoing, fig. 4 illustrates a graphical user interface 400 according to an exemplary embodiment, the graphical user interface 400 displaying a flat surface on a digital model 402 of a patient's teeth 404 (e.g., the back right or back left three teeth). For example, as described above, the digital model 402 may show the teeth 404 determined to have flatter occlusal surfaces according to

operations

206 and 208 of the method 200. A digital model 402 is shown in fig. 4, such that the occlusal surfaces of the patient's teeth 404 are exposed. As shown in FIG. 4, the digital model 402 is formed of a number of polygons 406 connected at edges 408. In the graphical user interface 400, the faces of the plurality of polygons 406 have been deselected (e.g., because the faces have a face normal vector with a z-component less than 0.85), thereby creating a deselected region 410. In addition, the faces of the plurality of polygons 406 have been selected (e.g., because the faces have a face normal vector with a z-component greater than or equal to 0.85), thereby creating a flat surface 412 in the digital model 402.

More specifically, referring to fig. 5, a graphical user interface 400 displaying a digital model 402 is shown from another view along the occlusal surface of a patient's teeth 404. As shown in fig. 5, the model is formed of polygons 406 connected at edges 408. In addition, surface normals 414 have been calculated for each polygon 406, and these surface normals 414 are also shown in FIG. 5. Polygons 406 having a face normal 414 with a z-component greater than or equal to a threshold value (e.g., 0.85) have been selected, where consecutive selected polygons 406 form a flat surface 412 in digital model 402.

Referring back to FIG. 2, at operation 212, a best fit line is determined between the planar surfaces. In some embodiments, once a flat surface has been selected for the posterior teeth, the appliance marking computing system 104 determines the centroid (e.g., the central average) of each flat surface. For example, the centroid is determined by taking the average of the x-and y-components of the polygons that make up the flat surface. A best fit line is then drawn between the centroids (e.g., through at least three to five centroids of a flat surface). The best fit line represents a path that may be used to etch the mark on the dental appliance because the best fit line defines a flat path or "flattest path" (when viewed from the z direction) along which the mark may be etched. In some embodiments, the best fit line defining the potential etch path is up to 20mm long, however, it will be appreciated that longer or shorter etch paths may be used (e.g., 30mm long etch path, 10mm long etch path, etc.).

For example, referring to fig. 6, a graphical user interface 400 is shown displaying a digital model 402 along the occlusal surfaces of a patient's teeth 404. As shown in fig. 6, the center of each polygon 406 that makes up digital model 402 (e.g., the position of face normal 414 is shown at the center in fig. 5) is shown as point 416. A selected flat surface 412 of the digital model 402 is also shown. Thus, at operation 212 of the method 200, the centroid of each of the flat surfaces 412 may be calculated and a best line may be fitted to the centroids to create a "flattest path" for marking the dental appliance corresponding to the digital model 402.

Referring back to fig. 2, at operation 214, the dental appliances are marked along the best-fit line. For example, the mark is configured as a string of text etched along a best-fit line using marking system 106 (e.g., a laser etching system, a CNC system, or other etching system). Accordingly, the appliance marking computing system 104 is configured to provide a best fit line to the marking system 106 for etching. In some arrangements, the text or other indicia is configured such that the text fits along an etch path of 7mm-12mm defined by a best fit line (e.g., extending along a portion of the first tooth and the second tooth included in the posterior tooth portion).

Further, in some embodiments, operation 214 includes determining a layout of the marks along the best fit line prior to etching the marks. As an example, as described above, the appliance indicia computing system 104 may determine how many indicia (e.g., text) will fit along a given flat surface, including along a best fit line, and based on this determination, create a layout of the indicia to be used in etching the dental appliance. Further, in some embodiments, multiple appliances may be manufactured from a single physical model corresponding to the digital model. Thus, the appliance indicia computing system 104 may determine or receive individual indicia for each dental appliance and determine the layout of each indicia for its associated dental appliance prior to etching the dental appliance. In some embodiments, a set of three appliances is manufactured from each physical model (e.g., hard, medium, and soft or thin, thicker, and thickest), and each appliance in the set is labeled at the same location while other sets of appliances of the same patient are labeled at different locations.

As used herein, the terms "approximately", "about", "substantially" and similar terms are intended to have a broad meaning consistent with the common accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Those skilled in the art who review this disclosure will appreciate that these terms are intended to allow a description of certain features described and claimed without limiting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted to indicate that: insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the claims that follow.

It should be noted that the term "exemplary" and variations thereof as used herein to describe the various embodiments is intended to indicate: these embodiments are possible examples, representations, or illustrations of possible embodiments (and these terms are not intended to imply that these embodiments are necessarily special or highest-level examples).

The term "couple" and variations thereof as used herein means that two members are directly or indirectly connected to each other. Such a connection may be fixed (e.g., permanent or fixed) or movable (e.g., removable or releasable). Such a connection may be achieved with two members being directly coupled to each other, wherein the two members are coupled to each other using a separate intervening member and any additional intermediate members coupled to each other, or wherein the two members are coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If "coupled" or variations thereof are modified by additional terms (e.g., directly coupled), the general definition of "coupled" provided above is modified by the plain language meaning of the additional terms (e.g., "directly coupled" means the connection of two members without any separate intervening members), resulting in a narrower definition than the general definition of "coupled" provided above. This coupling may be mechanical, electrical or fluid.

As used herein, the term "or" is used in its inclusive sense (and not in its exclusive sense) such that when used in conjunction with a list of elements, the term "or" means one, some, or all of the elements in the list. Unless specifically stated otherwise, connection language (e.g., at least one of the phrases "X, Y and Z") is understood to mean that the element can be X, Y, Z; x and Y; x and Z; y and Z; or X, Y and Z (i.e., any combination of X, Y and Z). Thus, unless otherwise specified, such conjunctive language is not generally intended to imply that certain embodiments require at least one of X, at least one of Y, and at least one of Z to all be present.

References herein to element positions (e.g., "top," "bottom," "above," "below") are merely used to describe the orientation of the various elements in the figures. It should be noted that the orientation of the various elements may differ according to other exemplary embodiments, and such variations are intended to be covered by the present disclosure.

The hardware and data processing components for implementing the various processes, operations, illustrative logics, logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with at least one of the following: a general purpose single-or multi-chip processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some embodiments, certain processes and methods may be performed by circuitry that is specific to a given function. The memory (e.g., memory unit, storage device) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage) for storing data and/or computer code to complete or facilitate the various processes, layers, and modules described in this disclosure. The memory may be or include volatile memory or non-volatile memory, and may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in this disclosure. According to an exemplary embodiment, the memory is communicatively connected to the processor via the processing circuitry and includes computer code for performing (e.g., by the processing circuitry or the processor) one or more processes described herein.

The present disclosure contemplates methods, systems, and program products on any machine-readable media for accomplishing the various operations. Embodiments of the present disclosure may be implemented using an existing computer processor or by a special purpose computer processor of an appropriate system introduced for this or other purposes or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. For example, machine-executable instructions comprise instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

Although the figures and descriptions may show a specific order of method steps, the order of the steps may differ from what is depicted and described, unless otherwise indicated above. Further, two or more steps may be performed simultaneously or partially simultaneously, unless otherwise indicated above. Such variations may depend, for example, on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the present disclosure. Likewise, software implementations of the described methods can be accomplished with standard programming techniques with rule based logic and other logic to accomplish the various connection steps, processing steps, comparison steps and decision steps. It is important to note that the construction and arrangement of the system and method of marking dental appliances as shown in the various exemplary embodiments is illustrative only. In addition, any element disclosed in one embodiment may be combined with or used together with any other embodiment disclosed herein. It should be understood that other elements of the various embodiments may be combined or used with any of the other embodiments disclosed herein.

Claims

1. A method for marking a dental appliance, comprising:

receiving a digital model corresponding to a dental appliance, the digital model including an arch, the arch including a plurality of teeth;

determining whether a portion of a tooth on the right or left side of the dental arch includes a flatter occlusal surface and selecting a portion having the flatter occlusal surface;

identifying surfaces on the teeth of the selected portion that are flat relative to other surfaces on the teeth of the selected portion;

determining a best fit line between the planar surfaces; and

marking the dental appliance with a mark based on the best fit line.

2. The method of claim 1, wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of teeth; and is

Wherein determining whether the portion of the teeth on the right or left side of the dental arch includes a flatter occlusal surface comprises: determining whether the portion of the tooth to the right or left of the dental arch includes a flatter occlusal surface based on surface normal vectors of the plurality of polygons.

3. The method of claim 2, wherein determining whether the portion of the tooth on the right or left side of the dental arch includes a flatter occlusal surface and selecting the portion having the flatter occlusal surface further comprises:

determining a surface normal vector for each polygon representing the occlusal surface in the digital model;

determining a z-direction component of each surface normal vector;

determining an average z-direction component for each tooth portion; and

selecting the portion having the average z-direction component closer to 1.

4. The method of claim 1, wherein the digital model includes a plurality of polygons representing the occlusal surfaces of teeth, and wherein identifying surfaces on the selected portion of teeth that are flat relative to other surfaces on the selected portion of teeth includes:

determining a surface normal vector for each polygon representing the occlusal surface of the selected portion in the digital model;

determining a z-direction component of each surface normal vector; and

each set of consecutive polygons having a face normal z-direction component greater than or equal to a threshold is identified as a flat surface.

5. The method of claim 4, wherein the threshold is 0.85.

6. The method of claim 1, wherein determining the best fit line between the planar surfaces comprises:

determining a centroid of each planar surface; and

the best fit line between centroids is determined.

7. The method of claim 1, wherein marking the dental appliance based on the best fit line comprises etching the dental appliance with the mark using a laser.

8. The method of claim 1, wherein the indicia is a string of alphanumeric characters.

9. A system for marking a dental appliance, comprising:

processing circuitry comprising at least one processor and a memory storing instructions that, when executed by the at least one processor, cause the processing circuitry to:

identifying a flat surface on a selected portion of teeth that is flat relative to other surfaces on the selected portion of teeth; and

determining a best fit line between the planar surfaces; and

a marking system configured to mark the dental appliance with a mark based on the best fit line.

10. The system of claim 9, wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of teeth; and is

Wherein the instructions cause the processing circuitry to determine whether the portion of the tooth to the right or left of the dental arch includes a flatter occlusal surface based on a surface normal vector of the plurality of polygons.

11. The system of claim 10, wherein the instructions further cause the processing circuitry to determine whether the portion of the tooth to the right or left of the dental arch includes a flatter surface and select the portion having the flatter occlusal surface by:

determining a z-direction component of each surface normal vector;

determining an average z-direction component for each tooth portion; and

selecting the portion having the average z-direction component closer to 1.

12. The system of claim 9, wherein the digital model includes a plurality of polygons representing the occlusal surfaces of the teeth, and wherein the instructions further cause the processing circuitry to identify surfaces on the selected portion of teeth that are flat relative to other surfaces on the selected portion of teeth by:

determining a z-direction component of each surface normal vector; and

13. The system of claim 12, wherein the threshold is 0.85.

14. The system of claim 9, wherein the instructions further cause the processing circuit to determine the best fit line between the planar surfaces by:

determining a centroid of each planar surface; and

the best fit line between centroids is determined.

15. The system of claim 9, wherein the marking system is a laser etching system.

16. The system of claim 9, wherein the indicia is a string of alphanumeric characters.

17. A memory storing instructions that, when executed by a processor, cause a system to:

determining a best fit line between the planar surfaces; and

providing the best fit line to a marking system configured to mark the dental appliance with a mark based on the best fit line.

18. The memory of claim 17, wherein the digital model comprises a plurality of polygons representing the occlusal surfaces of teeth, and wherein the instructions further cause the system to determine whether the portion of the teeth on the right or left side of the dental arch comprises a flatter surface and select the portion having the flatter occlusal surface by:

determining a z-direction component of each surface normal vector;

determining an average z-direction component for each tooth portion; and

selecting the portion having the average z-direction component closer to 1.

19. The memory of claim 17, wherein the digital model includes a plurality of polygons representing the occlusal surfaces of teeth, and wherein the instructions further cause the system to identify surfaces on the selected portion of teeth by:

determining a surface normal vector for each polygon forming the occlusal surface of the selected portion in the digital model;

determining a z-direction component of each surface normal vector; and

20. The memory of claim 17, wherein the instructions further cause the system to determine the best fit line between the planar surfaces by:

determining a centroid of each planar surface; and

the best fit line between centroids is determined.